What are curves used to transition vehicles from a straight path to a curved path typically called?

The term that refers to curves used to transition vehicles from a straight path to a curved path is "transition curve." These curves are designed to gradually change the alignment of a roadway, allowing vehicles to move more smoothly and safely from a straight section into a curved section.

Transition curves serve important engineering functions: they help to reduce the lateral acceleration experienced by vehicles, increasing comfort and safety for drivers. They also provide the necessary space for vehicles to adjust their steering input more gradually, which is especially important at higher speeds.

The concept of a transition curve is rooted in the understanding of how vehicles behave when changing direction. By implementing these curves, roadways can prevent abrupt shifts that may otherwise lead to instability or discomfort.